System and method for tumor analysis and real-time biopsy guidance

A system and method for molecular breast imaging (MBI) provides enhanced tumor analysis and, optionally, a real-time biopsy guidance. The system includes a detector head including a gamma ray detector and a collimator. The collimator include multiple collimation sections having respectively different spatially-oriented structures. In addition or alternatively, the multiple collimating section have respectively different collimation characteristics. An image of the tissue acquired with the system may include spatially separate image portions containing image information about the same portion of the imaged tissue. A system is optionally configured to acquire updatable images to provide real-time feedback about the biopsy procedure.